1. Field of the Invention
This invention relates to the construction of electromagnetic relays.
2. Description of Prior Art
For relays which must meet exacting performance requirements, such as in the aerospace industry, it is necessary that the fixed and movable contacts of the relay have a predetermined spatial relationship. Otherwise the performance and reliability of the relay are impaired. The tolerances build up in manufacture and assembly of the relay to a degree such that adjustmens of the relative contact positions are necessary. In the past this has been accomplished by completing the assembly of the relay except for the housing, and then manually bending the supports for the fixed contacts to obtain a desired value of contact over-travel, contact pressure or a combination of both. This operation takes a highly skilled operator who has a basic knowledge of relay operation in order to understand what adjustments should be made to meet specifications. Considerable manual dexterity is required in bending the contact supports by means of pliers or other hand tools to effect an acceptable setting. Hence, contact adjustment has been a relatively slow and expensive operation. Moreover, the results have been inaccurate and inconsistent. Hand manipulation of tools and force gauges makes it quite difficult for even the most capable personnel to accomplish the accuracy of adjustment needed by such relays. Results vary from operator to operator and for any one person the adjustments may not be consistent between various times when the adjusting operations take place.